JP2003194018A - Elbow with built-in straightening guide vane and cavitation tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elbow with built-in straightening guide vanes achieving a uniform flow with identical flow velocity distribution after passing through the straightening guide vanes, and a cavitation tunnel having the elbow with the built-in straightening guide vanes. <P>SOLUTION: Each of straightening guide vanes 23 is divided into three blocks 23A, 23B, 23C each having a mutually equal attack angle. The straightening guide vanes 23 in the blocks 23A, 23B, 23C are arranged so that the straightening guide vanes 23 in the outside block 23C have a smaller attack angle and the straightening guide vanes 23 in the inside block 23A have a larger attack angle with the attack angle of the straightening guide vanes 23 in the block 23B arranged in a center, as a criterion. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elbow with flow straightening guide vanes having a flow straightening vane which forms a curved flow passage and uniformly regulates the flow of fluid flowing out from the curved flow passage, and an elbow containing the flow straightening guide vanes. It relates to a cavitation tunnel equipped with.

[0002]

2. Description of the Related Art An example of a conventional cavitation tunnel equipped with an elbow containing straightening guide vanes will be described below with reference to the plan sectional view of FIG. The cavitation tunnel shown in the figure is of a circulation type in which a water stream circulates, a circulation pump 1 for forming a water stream, a pump housing body 2 that covers the periphery of the circulation pump 1 and forms a circular cross-section flow path, A deformed cylinder 3 that is connected to the downstream side of the pump housing body 2 and that gradually changes the flow passage cross-sectional shape from a circular cross-section flow passage to a square cross-section flow passage.
An elbow 4 having a straightening guide vane connected to the downstream side of the deformed barrel 3 to bend the water flow at a substantially right angle; a straight pipe barrel 5 connected to the downstream side of the elbow 4 having a straightening guide vane; Torso 5
Of the elbow 6 having a straightening guide vane connected to the downstream side of the elbow 6 for bending the water flow at a substantially right angle, and a contraction cylinder 7 connected to the downstream side of the elbow 6 having the straightening guide vane to reduce the flow passage cross-sectional area and accelerate the water flow. And a measuring cylinder 8 connected to the downstream side of the contraction cylinder 7 for accommodating an object to be measured (not shown) such as a hull model, and connected to the downstream side of the measuring cylinder 8 to decelerate the water flow. A diffusion cylinder 9, an elbow 10 with a straightening guide vane that is connected to the downstream side of the diffusion barrel 9 and bends the water flow at a substantially right angle, and a diffusion that is connected to the downstream side of the elbow 10 with the straightening guide vane to further reduce the water flow. A cylinder 11 and an elbow 12 with a rectifying guide blade that is connected to the downstream side of the diffusion cylinder 11 and bends the water flow at a substantially right angle.
And a deformed cylinder 13 that is connected between the downstream side of the elbow 12 including the rectifying guide vanes and the pump housing cylinder 2 and that gradually changes the flow passage cross-sectional shape from a square cross-section flow passage to a circular cross-section flow passage. Has been done.

In this cavitation tunnel, the water flow W sent by the circulation pump 1
However, it circulates in the clockwise direction on the paper. The water flow W at this time is the elbows 4, 6, 10, 1 with each rectifying guide vane.
The flow is bent at a substantially right angle each time it passes through 2, and in order to reduce the pressure loss generated in the water flow W at that time, the flow guides are provided inside the elbows 4, 6, 10, 12 with the flow guide guide vanes. Equipped with wings.

This conventional straightening guide vane will be described below with reference to FIG. 9 using the elbow 10 containing the straightening guide vane as an example. As shown in the figure, the elbow 10 with flow straightening guide vanes includes an elbow 15 forming a curved flow path, and a plurality of flow straightening guide vanes 16 arranged in the elbow 15 so as to be parallel to each other. It is configured. The elbow 15 includes a substantially L-shaped bottom wall 15a, an inner wall 15b standing inside the bottom wall 15a, an outer wall 15c standing outside the bottom wall 15a, and the inner wall 15b and the outer wall 15c.
And an upper wall (not shown) connected to the upper edge of the above, and these form a right-angled channel having a rectangular channel cross section.

Each of the straightening guide vanes 16 is an arc plate having a plane cross section of an arc shape and having a height dimension in the direction perpendicular to the plane of the drawing. These straightening guide vanes 16
Are arranged and fixed such that they have an angle of attack equal to the inflow angle of the water flow W and are parallel to each other. Then, the water flow W flowing into the elbow 15 gradually changes its direction along the curved surface shape of each straightening guide vane 16, and finally flows out in a state of being bent at a substantially right angle.

[0006]

By the way, the conventional elbow 10 including the above-described conventional straightening guide vanes has the problems described below. That is, it is desirable that the water flow W after passing through each of the flow control guide vanes 16 is a uniform flow where the flow velocity is uniform at any point, but this is verified using CFD calculation (computational fluid dynamics calculation). When I try,
As shown in FIG. 8, it was confirmed that the flow velocity uniform region was biased to bulge outward and a flow stagnation region was generated further downstream thereof. When such a biased or stagnant region of the flow velocity uniform region occurs, the water flow W flowing into the circulation pump 1 is disturbed to cause noise due to cavitation, or the water flow W flowing into the measuring cylinder 8 is disturbed. May occur, which may cause a problem such as adversely affecting measurement accuracy.

The present invention has been made in view of the above circumstances, and includes an elbow with a straightening guide vane capable of obtaining a uniform flow velocity distribution after passing through the straightening guide vane, and the elbow with the straightening guide vane. It is intended to be provided with a cavitation tunnel equipped with an elbow.

[0008]

The present invention adopts the following means in order to solve the above problems. That is, the elbow with flow straightening guide vanes according to claim 1 has a flow straightening guide vane including an elbow having a curved flow passage and at least three or more flow straightening guide vanes provided inside the curved flow passage. In the elbow, each of the straightening guide vanes has an attacking angle outside the first central straightening guide vane with reference to an attacking angle of the first central straightening guide vane arranged at a central position of the curved flow path. Is smaller, and the angle of attack is larger inside the first central straightening guide vane.

According to the elbow with the flow straightening guide vanes according to the first aspect, the fluid flowing when passing through the flow straightening guide vanes is
The flow in the region inside the first central straightening guide vanes is bent by the straightening guide vanes having a large angle of attack with a smaller curvature than the flow flowing in the vicinity of the first central straightening guide vanes. Further, the flow in the region outside the first central straightening guide vane is bent by the straightening guide vane having a small angle of attack with a curvature larger than that of the flow flowing in the vicinity of the first central straightening guide vane. . This makes it possible to prevent the uniform flow after passing through the flow control guide vanes from forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional case.

The elbow with flow straightening guide vanes according to claim 2 has an elbow with a curved flow passage, and a plurality of flow straightening guide vanes provided inside the curved flow passage. In the above, each of the straightening guide vanes is divided into a plurality of first blocks having an equal angle of attack, and each of the straightening guide vanes in the first block is arranged in the curved flow path in each of the first blocks. The angle of attack of each of the straightening guide vanes in the first block outside the first central block with reference to the angle of attack of each of the straightening vanes in the first central block arranged at the central position of Is smaller than the first central block
In each block, the straightening guide vanes are arranged such that the angle of attack of the vanes is large.

According to the elbow having the flow straightening guide vanes according to the second aspect, the fluid flowing through each of the first blocks flows through the first block inside the first central block. With the straightening guide vanes with a large angle of attack,
The flow is bent with a smaller curvature than the flow through the central block of. Further, the flow in the region outside the first central block is bent with a curvature larger than that of the flow in the first central block due to the straightening guide vanes having a small angle of attack. This makes it possible to prevent the uniform flow after passing through the flow control guide vanes from forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional case. Further, when the number of flow guide vanes is relatively large, it is better to combine them into a plurality of blocks (first block) and change the angle of attack between the blocks as in the present invention. This makes it easier to manufacture as compared with the case where the corners are adjusted.

The elbow with flow straightening guide vanes according to claim 3 is the elbow with flow straightening guide vanes according to claim 1 or 2, wherein the angle of attack of each of the flow straightening guide vanes is α. Then, α = 0 °, which is equal to the inflow angle of the fluid flowing in the elbow, and 0 inside the reference.
Within the range of ° <α ≦ + 5 °, and outside the reference,
It is characterized in that it is within the range of 0 °> α ≧ −5 °.

According to the elbow including the straightening guide vanes of the third aspect, if the difference between the reference angle of attack of the straightening guide vanes and the angles of attack of the other straightening vanes is too wide,
There is a possibility that the throat area between the adjacent blades is greatly different, the distortion of the velocity distribution at the blade outlet increases, or the flow on the blade surface separates. In order to reliably obtain a uniform flow without causing this problem, it is preferable to set the angle of attack α of each straightening guide vane within the above range according to the position in the curved flow passage.

An elbow with flow straightening guide vanes according to a fourth aspect of the present invention is the elbow with flow straightening guide vanes having an elbow having a curved flow passage and a flow straightening guide vane provided inside the curved flow passage. The straightening guide vanes are arc-shaped plates supported between a pair of wall surfaces, and when divided into a wall surface vicinity portion close to each wall surface and a central portion located between these wall surface vicinity portions, The angle of attack is set to be larger than that of each wall surface vicinity portion, and the angle of attack of each partition wall surface vicinity portion is made equal to the inflow angle of the fluid flowing in the elbow.

According to the elbow having the flow straightening guide vanes according to the fourth aspect, among the flows passing through the flow straightening guide vanes, those flowing along the respective wall surfaces tend to have a reduced flow velocity due to the formation of the boundary layer. However, in the present invention, the angle of attack in the vicinity of each wall surface is made equal to the inflow angle, so that the pressure loss when passing through this can be suppressed low. In addition, in the central portion located between the portions near each wall surface, since the influence of the boundary layer is less likely to occur, the flow velocity tends to be higher than other portions, but in the present invention, the inflow angle of the fluid flowing therethrough Since the angle of attack is made larger than that, it becomes possible to increase the pressure loss and decrease the flow velocity. In this way, it is possible to reduce the velocity difference of the fluid after passing through the flow straightening guide vanes in the direction from one wall surface supporting the flow straightening guide vanes toward the other wall face.

An elbow with flow straightening guide vanes according to a fifth aspect is the elbow with flow straightening guide vanes according to claim 4, wherein when the angle of attack of each of the flow straightening guide vanes is β, a portion near each wall surface is , Β = 0 °, which is equal to the inflow angle of the fluid flowing in the elbow, and 0 ° <β in the central portion.
It is characterized in that it is within the range of ≦ + 5 °.

According to the elbow including the straightening guide vanes of the fifth aspect, when the difference between the attack angle in the vicinity of each wall surface and the attack angle in the central portion is excessively widened, conversely, the flow velocity in the central portion is increased. The flow velocity becomes slower than the flow velocity in the vicinity of each wall surface, which may cause a problem that it is difficult to form a uniform flow. In order to surely obtain a uniform flow without causing this problem, it is preferable to set the angle of attack β of each part of the straightening guide vanes within the above range.

The elbow with flow straightening guide vanes according to a sixth aspect has a flow straightening guide vane including an elbow having a curved flow passage, and at least three or more flow straightening guide vanes provided inside the curved flow passage. In the entry elbow, each of the straightening guide vanes is turned outside the second central straightening guide vane on the basis of the turning angle of the second central straightening guide vane arranged at the central position of the curved flow path. The angle is smaller, and the turning angle is larger inside the second central straightening guide vane.

According to the elbow containing the flow straightening guide vanes of the sixth aspect, the fluid flowing through the flow straightening guide vanes is
The flow in the region inside the second central straightening guide vane is bent by the straightening guide vane having a large turning angle with a smaller curvature than the flow flowing in the vicinity of the second central straightening guide vane. Further, in the case of flowing in the region outside the second central straightening guide vane, the flow is bent with a curvature larger than the flow flowing in the vicinity of the second central straightening guide vane by the straightening guide vane having a small turning angle. . This makes it possible to prevent the uniform flow after passing through the flow control guide vanes from forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional case.

An elbow with flow straightening guide vanes according to a seventh aspect of the present invention has an elbow with a curved flow passage and a plurality of flow straightening guide vanes provided inside the curved flow passage. In the above, each of the straightening guide vanes is divided into a plurality of second blocks having the same turning angle, and the respective straightening guide vanes in the second blocks are
Of the respective second blocks, a second outer side of the second central block is based on the turning angle of each straightening guide vane in the second central block arranged at the central position of the curved flow path. In the block, the turning angle is small, and in the second block inside the second central block,
It is characterized by a large turning angle.

According to the elbow having the flow straightening guide vanes of the seventh aspect, when the fluid passing through each of the second blocks flows through the second block inside the second central block, The straightening vanes with a large turning angle allow the flow to be bent with a smaller curvature than the flow through the second central block. Further, the flow in the region outside the second central block is bent with a curvature larger than that of the flow in the second central block due to the straightening guide vanes having a small turning angle. This allows
It becomes possible to prevent the uniform flow after passing through the respective flow-straightening guide vanes from forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional case. In addition, when the number of rectifying guide vanes is relatively large, it is better to combine them into a plurality of blocks (second block) and change the turning angle between the blocks as in the present invention. This makes it easier to manufacture as compared with the case where the corners are adjusted.

The elbow with flow straightening guide vanes according to claim 8 is the elbow with flow straightening guide vanes according to claim 6 or 7, wherein the turning angle γ of each flow straightening guide vane when the reference is γ1. However, inside the reference, γ1
<Γ ≦ γ1 + 10 °, and outside the reference, γ1> γ ≧ γ1-10 °.

According to the elbow containing the straightening guide blades of the above-mentioned claim 8, if the difference between the reference turning angle of the straightening guide blades and the turning angle of the other straightening guide blades is excessively widened, they are adjacent to each other. There is a possibility that the throat areas between the blades are greatly different, the distortion of the velocity distribution at the blade row outlet is increased, or the flow on the blade surface is separated. In order to surely obtain a uniform flow without causing this problem, it is preferable to set the turning angle γ of each straightening guide vane within the above range according to the position in the curved flow passage.

A cavitation tunnel described in claim 9 is characterized in that the cavitation tunnel according to any one of claims 1 to 8 is provided. According to the cavitation tunnel described in claim 9, the flow passing through the elbow containing the flow guide vanes can be made into a uniform flow having a uniform flow velocity distribution, so that the pump causing the circulation causes cavitation and noise. You will be able to solve the traditional problems such as causing.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an elbow with rectifying guide vanes and a cavitation tunnel according to the present invention will be described below with reference to the drawings, but it goes without saying that the present invention is not limited to these. Is. In the description of each embodiment, the case where the elbow including the straightening guide vanes of the present invention is applied to the curved flow section of the cavitation tunnel will be described as an example.

[First Embodiment] First, a first embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a view showing a case where the elbow including the flow straightening guide vanes of the present embodiment is applied to a curved flow portion of a cavitation tunnel, and is a plan sectional view corresponding to a portion A of FIG. 8. In addition, FIG. 2 is a plan sectional view for explaining the definition of terms used to describe each of the straightening guide vanes installed in the elbow including the same straightening guide vanes. In addition, FIG. 3 is a plan sectional view comparing and picking up three representative three of the flow control guide vanes of the same embodiment.

The cavitation tunnel of the present embodiment is of a circulatory type in which a water flow flowing inside circulates, like the one described in the prior art with reference to FIG. A pump housing body 2 that covers the circumference of the pump 1 and forms a circular cross-section flow path, and is connected to the downstream side of the pump housing body 2 and gradually changes the flow path cross-sectional shape from the circular cross-section flow path to the square cross-section flow path. Deformed body 3
An elbow 4 having a straightening guide vane connected to the downstream side of the deformed barrel 3 to bend the water flow at a substantially right angle; a straight pipe barrel 5 connected to the downstream side of the elbow 4 having a straightening guide vane; Torso 5
Of the elbow 6 having a straightening guide vane connected to the downstream side of the elbow 6 for bending the water flow at a substantially right angle, and a contraction cylinder 7 connected to the downstream side of the elbow 6 having the straightening guide vane to reduce the flow passage cross-sectional area and accelerate the water flow. And a measuring cylinder 8 connected to the downstream side of the contraction cylinder 7 for accommodating an object to be measured (not shown) such as a hull model, and connected to the downstream side of the measuring cylinder 8 to decelerate the water flow. A diffusion cylinder 9, an elbow 10 with a straightening guide vane that is connected to the downstream side of the diffusion barrel 9 and bends the water flow at a substantially right angle, and a diffusion that is connected to the downstream side of the elbow 10 with the straightening guide vane to further reduce the water flow. A cylinder 11 and an elbow 12 with a rectifying guide blade that is connected to the downstream side of the diffusion cylinder 11 and bends the water flow at a substantially right angle.
And a deformed cylinder 13 that is connected between the downstream side of the elbow 12 including the rectifying guide vanes and the pump housing cylinder 2 and that gradually changes the flow passage cross-sectional shape from a square cross-section flow passage to a circular cross-section flow passage. Has been done.

The cavitation tunnel according to the present embodiment includes the elbows 4, 6, 10, 1 with the respective flow guide vanes.
Since the structure of 2 is particularly characteristic, a new reference numeral 20 is given to distinguish it from the conventional elbow containing the flow straightening guide vanes, and the structure will be described below. Since all four parts have substantially the same configuration, the part corresponding to the portion A in FIG. 8 will be described as a representative.

As shown in FIG. 1, an elbow 20 with flow straightening guide vanes according to the present embodiment has an elbow 22 in which a curved flow passage 21 that bends at a right angle is formed, and an elbow 22 arranged inside the curved flow passage 21, for example. It is configured to include 12 sheets of flow straightening guide blades 23. The elbow 22 is a substantially L-shaped bottom wall 22.
a and an inner wall 22b erected inside the bottom wall 22a,
An outer wall 22c provided upright on the outer side of the bottom wall 22a and an upper wall (not shown) connected to the upper edges of the inner wall 22b and the outer wall 22c are provided, and a right-angled channel having a rectangular channel cross section is formed by these. It is supposed to do.

Each of the straightening guide vanes 23 has an arcuate shape in which the flat cross-sectional shape shown in the same figure is convex from the inside of the curved flow path 21 to the outside thereof, and the height dimension is perpendicular to the paper surface of the figure. It is an arc plate with. Then, as shown in FIG. 2, when the arc extending direction of each straightening guide vane 23 is the width direction and the vertical direction of the drawing is the height direction,
A shaft 23a is passed through at a central position of the overall length c in the width direction and a central position of the plate thickness so as to penetrate in the height direction, and both ends of the shaft 23a are supported by the bottom wall 22a and the upper wall. It is like this. The angle of attack can be adjusted by rotating the shaft 23a around the axis. After the angle of attack is set, the angle of attack is fixed by a fixing means (not shown).

In the following description, the concave curved surface 23b side of each straightening guide vane 23 will be described as the belly side, and the convex curved surface 23c side will be described as the back side. Further, the angle formed by the center line of the front edge 23x with respect to the flow direction of the water flow W is defined as an attack angle α, and the angle formed by the center line of the front edge 23x and the center line of the rear edge 23y is 1
The angle subtracted from 80 ° is defined as the turning angle γ for explanation. By the way, in the case of the straightening guide vanes 23 of FIG. 2, the angle of attack α = 0 ° and the turning angle γ = 90 ° in which the angle of attack is equal to the inflow angle of the water flow W.

In this embodiment, as shown in FIGS. 1 and 3, each of the straightening guide vanes 23 has three blocks 23A, 23B and 23C (first block) having angles of attack equal to each other.
Blocks). The block 23B is a central block arranged at the central position of the curved flow path 21, the block 23A is an inner block arranged inside the flow path with respect to the block 23B, and the block 23C is a block 23B. It is an outer block that is placed on the outside. In addition, all the rectification guide vanes 2
3 have the same shape with equal turning angles γ.

In the block 23A, for example, four straightening guide vanes 23 are arranged so as to be parallel to each other. Similarly, in the blocks 23B and 23C, for example, 4
The straightening vanes 34 are arranged so as to be parallel to each other. Then, each block 23A, 23
When the straightening guide vanes 23 are compared between B and 23C, the angles of attack α are different.

That is, as shown in FIG.
3A (first central block), each straightening guide vane 23 has an angle of attack α = 0 ° equal to the inflow angle of the water flow W as a reference, and within the block 23A (inner block), the angle of attack α
Has a relatively large positive value, and in the block 23C (outer block), the angle of attack is adjusted so that the angle of attack α has a relatively small negative value. More specifically, with respect to the angle of attack α = 0 ° of the block 23B as a reference, the block 23A inside the reference has a value of 0.
Within the range of ° <α ≦ + 5 °, the block 23C outside the reference has a range of 0 °> α ≧ −5 °.

The water flow W flowing into the elbow 20 having the straightening guide vanes having the structure described above is supplied to the respective straightening guide vanes 2.
Gradually change the direction of the flow along the curved surface of 3,
Eventually, it flows out in a bent state at a substantially right angle. At this time, the water flow W passing through the blocks 23A, 23B, and 23C, which flows through the inner block 23A, is more likely to flow than the flow that flows through the central block 23B by the straightening guide vanes 23 having a large angle of attack. The flow can be bent with a small curvature. Also, the outer block 23C
The flow that flows through the flow path is bent by each straightening guide vane 23 having a small angle of attack, with a curvature larger than that of the flow flowing through the central block 23B. As a result, it is possible to prevent the flow of the entire uniform flow after passing through all the flow straightening guide vanes 23 from forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional case. .

As described above, in the elbow 20 including the straightening guide vanes of the present embodiment, the respective straightening vanes 23 have the three blocks 23A, 23B, 2 having the same angle of attack α.
3C and these blocks 23A, 23B, 23C
Each rectification guide vane 23 in each block 23A, 23
Block 23 located in the central position of B and 23C
With reference to the angle of attack α of each straightening guide vane 23 in B = 0 °, the angle of attack α of each straightening vane 23 becomes smaller in the outer block 23C, and the angle of attack α of each straightening vane 23 in the inner block 23A becomes smaller. Adopted a configuration in which the angle of attack α is increased. According to this configuration, each straightening guide vane 23
Since the uniform flow after passing through the flow passages properly flows without forming a knitting flow that is biased toward the outside of the curved flow path 21 as in the conventional case, on the wall surface 22c on the downstream side of the flow straightening guide vanes 23. It becomes possible to minimize the stagnation area caused by the boundary layer along the boundary layer. Therefore, it is possible to obtain a uniform flow with a uniform flow velocity distribution after passing through the respective flow control guide vanes 23.

Further, in the elbow 20 with straightening guide vanes of the present embodiment, the angle of attack α of each straightening guide vane 23 is set to α = 0 ° which is equal to the inflow angle of the water flow W in the central block 23B serving as the reference. , 0 ° <α in the inner block 23A
Within the range of ≦ + 5 °, 0 in the outer block 23C.
A configuration is adopted in which the range of °> α ≧ −5 ° is adopted. According to this configuration, it is possible to reliably make the flow after passing through the flow control guide vanes 23 a uniform flow having a uniform flow velocity distribution.

The cavitation tunnel of this embodiment employs a structure provided with the elbow 20 having the above-mentioned flow straightening guide vanes. According to this configuration, the flow passing through the elbow 20 including the rectifying guide vanes can be made into a uniform flow having a uniform flow velocity distribution, so that the conventional circulation pump 1 causes cavitation and causes noise. It becomes possible to solve the problem.

In the elbow 20 with the rectifying guide vanes of this embodiment, the angle of attack α is set for each of the blocks 23A, 23B, 23C, but the present invention is not limited to this, and one rectifying guide vane 23 is used. The angle of attack α may be set for each. That is, each straightening guide vane 23 is connected to the curved flow path 21.
Rectifying guide vane 23 arranged at the central position of the center rectifying guide vane 23 (central rectifying guide vane. 1 if the total number is odd, 2 if even
Sheet. ), The straightening guide vanes 2 of this reference
Outside of 3, the angle of attack becomes gradually smaller as it approaches the outer wall 22c, while at inside of the reference straightening guide vane 23, the angle of attack gradually increases as it approaches the inner wall 22b. It may be placed in. However, as in the present embodiment, the straightening guide vanes 2
When the number of sheets of 3 is relatively large, a plurality of blocks 23
A, 23B, and 23C (first block) are combined to change the angle of attack α between the blocks 23A, 23B, and 23C, which is easier to manufacture than when the angle of attack is adjusted for each sheet. Therefore, it can be said that it is more preferable because the elbow 20 with the rectifying guide vanes can be manufactured at low cost.

[Second Embodiment] Next, a second embodiment of the cavitation tunnel provided with the elbow including the flow straightening guide vanes of the present invention will be described below with reference to FIGS. 4 and 5. To do. Here, FIG. 4 is a perspective view showing the flow straightening guide vanes installed in the elbow with the flow straightening guide vanes of the present embodiment, and FIG. 5 is a plan view for explaining the shape of the flow straightening guide vanes. Is. The present embodiment is different from the first embodiment in the shape and angle of attack of each rectifying guide vane, so the following description will focus on this difference. The description is omitted because it is the same as the first embodiment. Further, in order to distinguish it from the straightening guide vanes 23 of the first embodiment, the straightening guide vanes of the present embodiment will be described with a new reference numeral 33.

The straightening guide vanes 33 of the present embodiment are arc-shaped plates supported between the bottom wall 22a and the top wall (between a pair of wall surfaces), and are near the wall surface near the bottom wall 22a and the top wall. 33a and a central portion 33b located between the wall surface neighboring portions 33a, the angle of attack β of the central portion 33b is made larger than the angle of attack β of each wall neighboring portion 33a, and each partition wall The angle of attack β of the near surface portion 33a is
It is made equal to the inflow angle of the water flow W flowing in the elbow 22. Furthermore, the angle of attack β in each part is β = 0 °, which is equal to the inflow angle in each wall surface vicinity portion 33a, and is set in the range of 0 ° <β ≦ + 5 ° in the central portion 33b. . Further, the rectification guide vanes 33 of the present embodiment are arranged in parallel so that a plurality of sheets (for example, 12 sheets) are parallel to each other.

In the prior art, of the flow of the water flow W passing through each straightening guide vane 33, the flow of the water flowing along the bottom wall 22a and the upper wall tends to decrease due to the formation of the boundary layer on the wall surface. Although there is a tendency, in the elbow with the rectifying guide vanes of this embodiment, the angle of attack β of each wall surface vicinity portion 33a is set to 0 ° which is equal to the inflow angle, so that the pressure loss when passing through this can be suppressed to a low level. become. Also,
Conventionally, in the central portion 33b located between the wall surface neighboring portions 33a, since the boundary layer is unlikely to be affected, the flow velocity tends to be higher than in other portions, but in the present embodiment, it flows there. Since the angle of attack β is made larger than the inflow angle of the water flow W, the pressure loss can be increased and the flow velocity can be reduced. In this way, each straightening guide vane 33
It is possible to reduce the difference in speed of the water flow W after passing through the flow control guide vanes 33 in the height direction of.

As described above, in the elbow including the straightening guide vanes of this embodiment, each straightening guide vane 33 has the bottom wall 2
2a and the wall portion 33a close to the upper wall, and the central portion 33b located between the wall portion 33a, the elevation angle β of the central portion 33b is made larger than that of each wall portion 33a. , Each partition wall surface vicinity portion 33a
The angle β of attack is set to 0 ° which is equal to the inflow angle of the water flow W. According to this configuration, each straightening guide vane 33
Since it is possible to reduce the velocity difference of the water flow W after passing through the flow control guide vanes 33 in the height direction of the flow velocity, the flow after passing through the flow control guide vanes 33 is changed to a uniform flow velocity distribution. It becomes possible to do.

Further, in the elbows containing the straightening guide vanes of this embodiment, the angle of attack β of the straightening guide vanes 33 is set to β = 0 °, which is equal to the inflow angle of the water flow W in the wall surface neighboring portions 33a,
In the central portion 33b, a configuration is adopted within the range of 0 ° <β ≦ + 5 °. According to this configuration, the flow after passing through the flow control guide vanes 33 can surely be a uniform flow having a uniform flow velocity distribution.

[Third Embodiment] A third embodiment of the cavitation tunnel provided with the elbow including the flow straightening guide vanes of the present invention will be described below with reference to FIGS. 6 and 7. To do. Here, FIG. 6 is a view showing the elbow with the rectifying guide vanes of the present embodiment, and is a plane cross-sectional view corresponding to part A of FIG. 8. Further, FIG. 7 is a plan view for explaining the shape of the same flow guide vanes. In this embodiment, the shapes and angles of attack of the respective rectifying guide vanes are particularly different from those of the first embodiment, and therefore, the difference will be mainly described below.
Others are the same as those in the above-described first embodiment, and description thereof will be omitted. Further, in order to distinguish it from the straightening guide blades 23 of the first embodiment, the straightening guide blades of the present embodiment will be described with a new reference numeral 43.

The elbow with the rectifying guide vanes of this embodiment is
Each of the straightening guide vanes 43 is divided into three blocks 43A, 43B, 43C (second blocks) having the same turning angle γ. The block 43B is a central block arranged at the central position of the curved flow path 21,
Further, the block 43A is an inner block arranged inside the flow path with respect to the block 43B, and the block 4A
3C is an outer block arranged outside the block 43B. In addition, all the rectification guide blades 43
Have equal angles of attack α = 0 °.

In the block 43A, for example, four straightening guide vanes 43 are arranged in parallel with each other. Similarly, in blocks 43B and 43C, for example, 4
The straightening vanes 43 are arranged so as to be parallel to each other. Then, each block 43A, 43
When the straightening guide vanes 43 are compared between B and 43C, the turning angles γ are different.

That is, each block 43A, 43B, 4
Of the 3C, the turning angle γ = γ1 of each straightening guide vane 43 in the block 43B (second central block) arranged at the central position of the curved flow path 21 is used as a reference, and each block in the outer block 43C The turning angle γ of the flow control guide vanes 43 is small, and the flow control guide vanes 4 are not moved in the inner block 43C.
The turning angle γ of 3 is large. Further speaking, when the turning angle γ of each of the blocks 43A, 43B, 43C is based on the turning angle γ of the central block 43A, the inner block 43A has a range of γ1 <γ ≦ γ1 + 10 °, In the outer block 43C, γ1> γ ≧ γ1-1
It is within the range of 0 °.

According to the elbow including the straightening guide vanes of the present embodiment having the above-described structure, the blocks 43A, 43
Block 4 in the middle of water flow W as it passes through B and 43C
What flows through the block 43A on the inner side of 3B is blocked by the rectifying guide vanes 43 having a large turning angle γ.
The flow can be bent with a curvature smaller than that of the flow. Further, the flow in the block 43C outside the central block 43B can be bent with a curvature larger than that of the flow in the block 43B by the flow straightening guide vanes 43 having a small turning angle γ. This allows
The uniform flow after passing through each straightening guide vane 43
It becomes possible to prevent the formation of a knitting flow that is biased toward the outside of the curved flow path as in the conventional case.

As described above, in the elbow including the straightening guide vanes of this embodiment, each straightening guide vane 43 is divided into three blocks 43A, 43B, 43C having the same turning angles.
Each of the straightening guide vanes 43 in the blocks 43A, 43B, 43C is divided into blocks 43A, 43B, 43C.
Among these, the turning angle γ of each straightening guide vane 43 is small in the outer block 43C with reference to the turning angle γ of each straightening vane 43 in the block 43B arranged at the central position of the curved flow path 21. In the block 43A, the structure in which the turning angle γ of each straightening guide vane 43 is large is adopted. According to this structure, the flow of the uniform flow after passing through the respective flow control guide vanes 43 properly flows without forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional case. On the downstream side of the blade 43, the stagnation area due to the boundary layer along the wall surface of the flow path can be minimized. Therefore, it is possible to obtain a uniform flow having a uniform flow velocity distribution after passing through the flow control guide vanes 43.

Further, the elbow with the rectifying guide vanes of this embodiment has a turning angle γ for each block 43A, 43B, 43C.
However, when the turning angle γ of the central block 43A is used as a reference, in the inner block 43A, γ1 <γ ≦ γ1 + 10
Within the range of °, γ1> γ in the outer block 43C.
A configuration is adopted within the range of ≧ γ1-10 °. With this configuration, the flow after passing through the flow control guide vanes 43 can be surely made into a uniform flow having a uniform flow velocity distribution.

Although the turning angle γ is set for each of the blocks 43A, 43B, 43C in the elbow with the rectifying guide vanes of this embodiment, the present invention is not limited to this, and each rectifying guide vane 43 is not limited to this. The turning angle γ may be set to. That is, each straightening guide vane 43 is connected to the curved flow path 21.
Straightening guide vanes 43 (central straightening vanes. 1 if the total number is odd, 2 if the total is even)
Sheet. On the outside of the reference straightening guide vanes 43, the turning angle gradually decreases toward the outer wall 22c, while on the other hand, inside the reference straightening guide vanes 43, the turning angle becomes smaller. The turning angle may be gradually increased toward the inner wall 22b. However, when the number of the rectifying guide vanes 43 is relatively large as in the present embodiment, the plurality of blocks 4
3A, 43B, 43C (second block) are combined to change the turning angle γ among the blocks 43A, 43B, 43C, which is easier to manufacture than when the turning angle is adjusted for each sheet. Therefore, it can be said that it is more preferable because the elbow with the rectifying guide vanes can be manufactured at low cost.

In the first to third embodiments described above, the case where the elbow with the flow straightening guide vanes of the present invention is applied to a cavitation tunnel has been described as an example, but it is applied to other uses such as a wind tunnel device. Of course, it is okay. Further, in the first to third embodiments, the number of each of the rectification guide vanes installed in the elbow with the rectification guide vanes is 12, but not limited to this, 3 to 1
The number of sheets may be one, or 13 or more.

[0054]

According to the elbow including the flow straightening guide vanes according to claim 1 of the present invention, the first straightening vanes each having the straightening guide vanes centrally arranged are provided.
Based on the angle of attack of the central rectifying guide vanes, we adopted a configuration in which the angle of attack is small on the outside and large on the inside. With this configuration, the flow of the uniform flow after passing through the respective flow control guide vanes correctly flows without forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional art, and therefore the flow of the flow control guide vanes is reduced. On the downstream side of
It becomes possible to minimize the stagnation area caused by the boundary layer along the wall surface forming the flow path. Therefore, it is possible to obtain a uniform flow with a uniform flow velocity distribution after passing through the respective flow guide vanes.

Further, in the elbow having the flow straightening guide vanes according to the second aspect, each flow straightening guide vane is divided into a plurality of first blocks having the same angle of attack, and the flow straightening guide vanes in the first block are separated from each other. , Of the first blocks, the angle of attack of each straightening vane is small in the outer first block with reference to the angle of attack of each straightening vane in the first central block located at the central position. Therefore, a configuration is adopted in which the straightening vanes of the straightening guide vanes are arranged to have a large angle of attack in the inner first block. With this configuration, the flow of the uniform flow after passing through the respective flow control guide vanes correctly flows without forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional art, and therefore the flow of the flow control guide vanes is reduced. On the downstream side of
It becomes possible to minimize the stagnation area caused by the boundary layer along the wall surface forming the flow path. Therefore, it is possible to obtain a uniform flow with a uniform flow velocity distribution after passing through the respective flow guide vanes. Further, when the number of flow guide vanes is relatively large, it is better to combine them into a plurality of blocks (first block) and change the angle of attack between the blocks as in the present invention. As compared with the case where the angle is adjusted, the manufacturing becomes easier, and the elbow with the rectifying guide blades can be manufactured at low cost.

Further, the elbow with flow straightening guide vanes according to claim 3 is the elbow with flow straightening guide vanes according to claim 1 or 2, wherein the angle of attack of each flow straightening guide vane is α. As a standard, α = 0 which is equal to the inflow angle of the fluid
.Degree., Inside the reference, 0.degree. <. Alpha..ltoreq. + 5.degree., And outside the reference, 0.degree..alpha..gtoreq.-5.degree. According to this configuration, the flow after passing through the flow control guide vanes can be surely made into a uniform flow having a uniform flow velocity distribution.

Further, in the elbow having the flow straightening guide vanes according to the fourth aspect, the flow straightening guide vanes are arc-shaped plates supported between the pair of wall faces, and the wall face vicinity portions near each wall face and the wall face vicinity portions. When divided into a central portion located between them, the elevation angle of the central portion is made larger than that of each wall surface vicinity portion, and the elevation angle of each partition wall surface vicinity portion is made equal to the fluid inflow angle. Adopted. According to this configuration, the velocity difference of the fluid after passing through the flow straightening guide vanes can be reduced in the direction from one wall surface supporting the flow straightening guide vanes toward the other wall surface. It is possible to make the flow of a uniform flow having a uniform flow velocity distribution.

Further, the elbow with the flow straightening guide vanes according to claim 5 is the elbow with the flow straightening guide vanes according to claim 4, in which the angle of attack of each flow straightening guide vane is β, in the vicinity of each wall surface. , Β = 0 °, which is equal to the inflow angle of the fluid,
In the central portion, a configuration is adopted within the range of 0 ° <β ≦ + 5 °. According to this configuration, the flow after passing through the flow straightening guide vanes can be surely made into a uniform flow having a uniform flow velocity distribution.

Further, in the elbow including the straightening guide vanes according to the sixth aspect, each of the straightening vanes has a small turning angle on the outer side with respect to the turning angle of the second central straightening guide vane arranged at the central position. Therefore, we adopted a structure that the turning angle becomes large on the inside. With this configuration, the flow of the uniform flow after passing through the respective flow control guide vanes correctly flows without forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional art, and therefore the flow of the flow control guide vanes is reduced. The stagnation area due to the boundary layer along the wall surface forming the flow channel can be minimized on the downstream side of the. Therefore, it is possible to obtain a uniform flow with a uniform flow velocity distribution after passing through the respective flow guide vanes.

Further, in the elbow including the straightening guide vanes according to the seventh aspect, each straightening guide vane is divided into a plurality of second blocks having equal turning angles, and the respective straightening guide vanes in these second blocks are divided. However, among the second blocks, the turning angle in the outer second block is based on the turning angle of each straightening guide vane in the second central block arranged at the central position of the curved flow path. The configuration is small and the turning angle is large inside the second block inside. With this configuration, the flow of the uniform flow after passing through the respective flow control guide vanes correctly flows without forming a knitting flow that is biased toward the outside of the curved flow path as in the conventional art, and therefore the flow of the flow control guide vanes is reduced. The stagnation area due to the boundary layer along the wall surface forming the flow channel can be minimized on the downstream side of the. Therefore, it is possible to obtain a uniform flow with a uniform flow velocity distribution after passing through the respective flow guide vanes. In addition, when the number of straightening guide vanes is relatively large, it is better to combine the blocks into a plurality of blocks (second blocks) and change the angle of attack between the blocks as in the present invention. As compared with the case where the angle is adjusted, the manufacturing becomes easier, and the elbow with the rectifying guide blades can be manufactured at low cost.

The elbow with flow straightening guide vanes according to claim 8 is the elbow with flow straightening guide vanes according to claim 6 or 7, wherein each of the straightening guide vanes is turned when the reference is γ1. When the angle γ is inside the reference, it is in the range of γ1 <γ ≦ γ1 + 10 °, and when it is outside the reference, it is in the range of γ1> γ ≧ γ1-10 °. According to this configuration, the flow after passing through the flow control guide vanes can be surely made into a uniform flow having a uniform flow velocity distribution.

Further, the cavitation tunnel described in claim 9 employs a structure provided with the elbow including the straightening guide vanes according to any one of claims 1 to 8. According to this configuration, the flow passing through the elbow with the rectifying guide vanes can be made into a uniform flow having a uniform flow velocity distribution, so that a conventional problem such as a pump causing circulatory noise due to cavitation occurs. Can be solved.

[Brief description of drawings]

FIG. 1 is a view showing a first embodiment in a case where the elbow with straightening guide vanes of the present invention is applied to a curved flow section of a cavitation tunnel, and is a plane cross-sectional view corresponding to part A of FIG. 8.

FIG. 2 is a plane cross-sectional view for explaining the definition of terms used for description of each straightening guide vane installed in the elbow containing the same straightening guide vane.

FIG. 3 is a plan sectional view comparing and picking up three representative three of the flow control guide vanes of the same embodiment.

FIG. 4 is a perspective view showing a second embodiment of flow straightening guide vanes installed in an elbow including the flow straightening guide vanes of the present invention.

FIG. 5 is a plan view for explaining the shape of the same flow guide vanes.

FIG. 6 is a diagram showing a third embodiment of an elbow with straightening guide vanes according to the present invention, and is a plan sectional view corresponding to part A of FIG. 8.

FIG. 7 is a plan view for explaining the shape of the same flow guide vanes.

FIG. 8 is a plan sectional view showing a cavitation tunnel equipped with a conventional elbow including a straightening guide vane.

9 is a view showing each rectification guide vane installed in the elbow including the same rectification guide vane, and is an enlarged view of a portion A of FIG. 8. FIG.

[Explanation of symbols]

20 ... Elbow with straightening guide vanes 21 ... Curved flow path 22 ... Elbow 23, 33, 43 ... Straightening guide vanes 23A, 23B, 23C ... the first block 23B ... first central block 33a ... Wall vicinity 33b ... central part 43A, 43B, 43C ... Second block 43B: second central block W: Water flow (fluid)

Claims (9)

[Claims] 1. An elbow with straightening guide vanes having a curved flow passage, and at least three or more straightening guide vanes provided inside the curved flow passage, wherein each straightening guide vane comprises: Based on the angle of attack of the first central straightening guide vane arranged at the central position of the curved flow path,
The straightening guide is arranged such that the angle of attack is smaller outside the first central straightening guide vane, and the angle of attack is larger inside the first central straightening vane. Elbow with feathers. 2. An elbow with a straightening vane having a curved flow passage and a plurality of straightening vanes provided inside the curved flow passage, wherein the straightening vanes are equal to each other. First with angle of attack
Of the first block, and each of the straightening vanes in the first block is divided into a plurality of blocks, and the straightening vanes in the first central block of the first block are arranged in the central position of the curved flow path. A first outside of the first central block based on the angle of attack of the blades
The blocks are arranged such that the angle of attack of each of the straightening guide vanes is small, and that the angle of attack of each of the straightening guide vanes is large in the first block inside the first central block. An elbow with straightening guide vanes. 3. The elbow with straightening guide vanes according to claim 1 or 2, wherein, when the angle of attack of each straightening guide vane is α, an inflow angle of a fluid flowing in the elbow is the reference. Equal to α =
0 °, inside the reference, 0 ° <α ≦ + 5 °, and outside the reference, 0 °> α ≧ −5 °
An elbow with straightening guide vanes characterized by being within the range. 4. An elbow with a straightening guide vane having a curved flow passage and an straightening vane provided inside the curved flow passage, wherein the straightening vane is supported between a pair of wall surfaces. When the arc-shaped plate is divided into a wall portion near each wall surface and a central portion located between the wall portions, the elevation angle of the central portion is higher than that of each wall portion. An elbow with straightening guide vanes, wherein the angle of attack of each partition wall surface is made equal to the inflow angle of the fluid flowing in the elbow. 5. The elbow with flow straightening guide vanes according to claim 4, wherein when the angle of attack of each flow straightening guide vane is β, the inflow angle of the fluid flowing in the elbow is close to each wall surface. Equal β = 0 °, 0 ° <β ≦ + in the central part
An elbow with straightening guide vanes, characterized in that it is within a range of 5 °. 6. An elbow with a straightening guide vane having a curved flow passage, and at least three or more straightening guide vanes provided inside the curved flow passage, wherein each straightening guide vane comprises: On the basis of the turning angle of the second central straightening guide vane arranged at the central position of the curved flow path, the turning angle becomes smaller outside the second central straightening guide vane, and the second central straightening vane is formed. An elbow with straightening guide vanes, which has a larger turning angle inside the guide vanes. 7. An elbow having a straightening vane having a curved flow passage and a plurality of straightening vanes provided inside the curved flow passage, wherein the straightening vanes are equal to each other. The second block having a turning angle is divided into a plurality of blocks, and each straightening guide vane in each of the second blocks has a second center located in the center of the curved flow path in each of the second blocks. On the basis of the turning angle of each straightening guide vane in the block, the turning angle is small in the second block outside the second central block, and the second block is inside the second central block. Inside, the elbow with straightening guide vanes is characterized by a large turning angle. 8. The elbow with straightening guide vanes according to claim 6 or 7, wherein the turning angle γ of each straightening guide vane when the reference is γ1 is γ1 <inside the reference. γ ≦ γ1 + 10
Within the range of ° and outside the reference, γ1> γ ≧ γ
An elbow with straightening guide vanes, which is in the range of 1-10 °. 9. A cavitation tunnel comprising the elbow containing the flow straightening guide vanes according to any one of claims 1 to 8.